Dip tube hanger



Sept. 10, 1968 1. D. JACOBSON DIP TUBE HANGER 3 Sheets-Sheet 1 Filed Feb. 17, 1965 INVENTOR. IRV! N D. JACOBS ON ATTORNEYS p 10, 1968 I. D. JACOBSON 3,400,951

DIP TUBE HANGER Filed Feb. 17, 1965 3 Sheets-Sheet 5 INVENTOR. IRVI N D. JACOBSON ATTORNEYS United States Patent 1 3,400,951 DIP TUBE HANGER Irvin D. Jacobson, 10 Bryn Mawr Drive, Painesville, Ohio 44077 Filed Feb. 17, 1965, Ser. No. 433,342 4 Claims. (Cl. 285-39) ABSTRACT OF THE DISCLOSURE A dip-tube combination for use with a hot water tank wherein the elongated tubular member is provided with an externally threaded sleeve molded about one end of the member to provide a unitary sleeve-member construction. The sleeve has external threads for engagement with a spud on a hot water tank for convenient insertion and replacement of the tubular member-sleeve combination within the tank. The internal surface of the sleeve is provided with tool pads for receiving an appropriate wrench when securing the sleeve and tube combination to the spud. The tubular member, in a preferred embodiment, is disclosed as being flared radially outwardly and has an aperture formed in the wall of the member for receiving a lug of the sleeve to provide a positive interlock between the tube and the sleeve. The sleeve is further provided with a flexible, circumferential flange extending longitudinally in the direction away from. the dip-tube member which is deformed radially and compressed into a sealing engagement with the threaded wall of the spud on the water heater when an inlet conduit is threaded into the spud.

This application relates to a hanger for dip tubes designed to be used with a hot water tank and the method of making such dip tube hangers.

A dip tube is a device used in water heaters to introduce the cold water at the bottom of the heater. Various materials have been employed to perform this function with a multiplicity of factors determining the precise composition of the tube. Included among these factors are local legislation, cost of the materials, safety requirements, possible galvanic action, and the particular length of guarantee on the heater combination. Since such a large number of factors are involved, giving rise tothe use of :dilferent types of materials indilferent combinations, the practice has been heretofore to utilize a particu-. lar method of attaching the dip tube to the tank depending on the specific material utilized. Through utilization of the principles of this invention, there is provided a dip tube hanger which can be applied to any material desired and give the heater manufacturer the economy, safety and long life which is required.

It is an object of this invention to provide a dip tube hanger.

It is another object of this invention to provide a novel method for forming such a hanger.

A still further object of the invention is to provide a dip tube hanger which is a molded cap formed from a wide variety of extrudable or plastifiable polyesters, resins or similar materials.

Another object of the invention is to provide a dip tube" hanger which-is formed from an extrudable or plastifiable material and molded to a tube which also can be of a wide variety of materials ranging from plastic to glass to metal. A r Still anotherobject of the invention is to provide a dip tube hanger which includes a portion thereon adapted to provide a. sealing means when the dip tube hanger is in use. t l I 3,400,951 Patented Sept. 10, 1968 Another object of the invention is to provide a dip tube hanger of a molded construction which includes a formed female portion providing a drive means for inserting the threaded cap into a female receptacle on the hot water tank.

Another object of the invention is the provision of a method for fabricating a dip tube hanger by an injection molding process which includes forming the tube receiving portions of the die halves slightly out of round so that the tube is flattened while in the'die with the natural resiliency of the tube material causing the tube to assume its round shape upon separation ofthe die halves.

A still further object of the invention is to provide a method of molding a dip tube hanger to a tube which includes the provision of an aperture in the tube adapted to receive the material of the dip tube hanger thereby providing a positive interlock between the tube and the hanger.

The above objects and others which will be more apparent upon a complete reading of the description which follows are accomplished by a tubular" body having an externally threaded sleeve molded to one end thereof. The threaded sleeve is provided with internal formed tool pads for engagement by a wrench. The tube is adapted to be inserted into a hot water tank through an internally threaded spud attached thereto and the sleeve of the combination is joined to the spud by cooperation of the threads. A copper nipple or equivalent is then threaded into the spud and against the end of the sleeve. The preferred embodiment of the sleeve includes a circumferential longitudinally extending sealing head for engagement with the inner end of the nipple which upon threaded engagement causes deformation of the bead into engagement with the threads of the female spud.

The method of making the dip tube combination includes the disposition of a precast tubular element in a mold and in surrounding relationship with a water cooled core or mandrel. The mold design is such that inserts of varying configurations may be employed to bring about any hanger or any external appearance desired. The core provides the shaping of the interior of the dip tube structure. With the tube in the die, the die is closed on the tube and granulated polypropylene thermoplastic material is then hopper fed into the heat chamber of the die. At the end of the molding and curing cycle, flow of the material is cut off automatically and the mold is separated so that the tube with the molded sleeve can be removed.

To the accomplishment of the foregoing and related ends, the following description sets forth in detail but a few approved means of carrying out the invention. Such disclosed means are not meant to be limiting inasmuch as they constitute but a few of the various ways in which the principles of the invention may be employed.

In the drawings wherein like reference numerals indicate like parts in the various views:

FIG. 1 is a side elevation view, partly in section, showing the dip tube construction as it is assembled in the water tank;

FIG. 2 is a schematic view of the tube as it is received in the dies preparatory to the molding operation;

FIG. 3 is a schematic view showing a further step of molding operation wherein the mandrel is inserted in the end of the tube;

FIG. 4 is a view taken along line 4-4 of FIG. 3;

FIG. 5 is a sectional view showing one form of the completed dip tube and hanger combination;

FIG. 6 is a view taken along line 6-6 of FIG. 5;

FIG. 7 is a view similar to FIG. 1 showing the dip tube structure in a modified joint on a hot water tank.

Referring first to FIG. 5, there is illustrated the preferred embodiment of the invention with the combination including a tubular elongated element 10 which may be of a wide variety of materials ranging from plastic to glass to metal. Secured at one end of the tube 10 is the dip tube hanger construction indicated generally by the reference numeral 11.

The dip tube hanger 11 comprises a molded cap which can be made from a wide variety of extrudable or plas'tifiable polyesters, resins or similar materials and in general comprises a sleeve construction 12 having external threads 13 formed on a portion thereof. The sleeve 12 xtends over a substantial portion of the end of the tube 10 and includes a radially inwardly directed lug portion 14 which extends through an aperture 10a in the tube 10 to provide a positive interlock between the tube and the sleeve. The end 15 of the tube 10, as shown in FIG. 5, is flared radially outwardly with the sleeve material disposed on either side of the flared portion 15. The sleeve 12 includes a through passage 16 which includes an internal hexagonal surface 17 designed to receive an appropriate wrench whereby the sleeve 12 may be secured to a threaded female member. In addition, the sleeve 12 includes an elongated longitudinally extending flexible portion 18 which is spaced axially of the threads 13. The circumferential flange 18 is flexible and adapted to be deformed upon the engagement of a pipe end with the flange 18, as will be described hereinafter.

The dip tube structure hereinbefore described is adapted to be received in a hot water tank in the manner illustrated in FIG. 1. Thus, the tank wall is indicated generally by the reference numeral 20 and includes an aperture 21. A spud 22 is welded to the tank Wall over the opening 21 and includes internal threads 23. The dimension of the threaded aperture in the spud 22 substantially coincides with the external dimension of the threaded sleeve 12 so that the tube 10 may be inserted through the aperture in the spud with the threads 13 on the hanger 11 being in threaded engagement with the threads 23 on the spud. Application of a wrench to the hexagonal wrench pads 17 formed in the interior of the hanger permits the threaded engagement of the hanger with the spud in the manner illustrated in FIG. 1.

To permit the introduction of water into the hot water tank, a conduit 26 is threaded into the spud 22 and engages the longitudinally extending flange 18 on hanger 11. As the tubing is threaded in the spud, the flange 18 is compressed and deformed radially into engagement with the female threads 23 thereby providing a seal between the hanger 11 and the spud 22. In addition to the scaling function, the flange 18 provides a stop for the inner end of the conduit 26 so that the possibility of cracking the sleeve 12 by undue overtightening is minimized.

A modified joint utilizing the hanger of FIG. 5 is illustrated in FIG. 7. It frequently happens that only a narrow spud 30 is secured to the wall of the hot water tank. In a situation such as that, there is not enough threaded area on the spud to accommodate both the hanger 11 and the end of the conduit 26. Accordingly, it is contemplated that the hanger above described will include the provision of the threads 13' being formed in an upwardly converging configuration as shown in FIG. 7. With this construction, the dip tube is adapted to be used in conjunction with a nipple 31 which is threaded into the spud 30. The dip tube hanger would be received through the passage in the nipple 31 and the passage in the spud 30, with the threads 13 on the hanger comprising, in effect, an extension of the threads 32 on the nipple 31. A connecting sleeve 33 with mating tapering threads 34 may be received in threaded engagement with the threads 13' and 32 as shown in FIG. 7. With this con- 4 r struction, it may be seen that the connecting sleeve 33 is the equivalent of the spud 22 illustrate d inFIG. 1 with the sleeve 33 also being adapted to receive the threaded end of the conduit 26. It is to be understood that the construction of the dip tube in FIG. 7 could include the longitudinally extending flange 18 similar to the construction shown in FIG. 5.

In both of the embodiments illustrated in FIGS. 1 and 7, it is contemplated that'the tube 10 will include the flared end 15. The end 15 is flared sufficiently so that the flare will retain the dip tube in the spud and maintain the hot water heater functional even should the hanger be destroyed or deteriorate.

The method of making the dip tube hanger construction hereinabove described is illustrated in FIGS. 2-4. In general, the dip tube combination is made by an injection molding process and involves the placement of the tube 10 in a mold 40 indicated schematically in FIG. 2. The mold is formed of two halves as shown in FIG. 4, an upper and lower half 40a and 40b respectively. A remov able insert 41a is received in the upper half of the mold and a corresponding removable insert 41b is placed in the lower half of the mold. The inserts are removable so that any external configuration of the hanger may be obtained.

Prior to the insertion of the tube 10 in the mold 40, an aperture 10a is placed near the end of the tube. Also, the end 15 of the tube is flared radially outwardly. With the tube received in the mold, a mandrel 45 is inserted in the mold with a reduced portion 46 of the mandrel being received in the flared end of the tubing. The end 46 includes a circular surface which is adapted to engage in close mating relationship with the interior of the tube 10. Intermediate the end 46 and the main body portion of the mandrel 45 is a hexagonally shaped surface 47 which develops the interior of the hanger in the desired configuration. A longitudinally extending bore 48 is formed in the mandrel 45 and provides means for cooling material to be applied to the end of the tube 10 in the event such a coolant is required.

With the tube and mandrel in the positions illustrated in FIG. 3, a granulated polypropylene thermoplastic material is fed into a heat chamber and thence into the mold through an opening 49. The molding temperature range is generally from 390 to 480 F. and pressure of 20,000 p.s.i. The entire molding and curing cycle is approximately 20 seconds. At the end of the cycle, the molten flow of polypropylene material is cut off automatically and the mold is designed to separate automatically so that the tube with the molded hanger can be removed.

It is to be understood that the molten material enters the aperture 10a in the tube 10 and is prevented from passing further by the cylindrical end 46 of the mandrel 45. Similarly, the material is received on either side of the flanged end 15 of the tube 10 and conforms to the threaded configuration of the inserts 41a and 41b to provide the dip tube construction illustrated in FIG. 5. The flange 18 is also formed by the inserts 41a, 41b.

An additional feature of the method above described is the formation of the tube receiving portions on the die in a slightly oval configuration so that the tube, when inserted between the closed die halves, is slightly distorted. When the molding process has been completed and the die halves are open, the natural resiliency of the tube 10 causes its return to its normal round configuration and thereby effects an automatic ejection of the dip tube con struction from the die.

Additional modifications and changes will suggest themselves to those having ordinary skill in the art. Changes such as these are contemplated by the principles of this invention so that, although for ease of description the principles of the invention have been set forth in connection with but a few illustrated embodiments, it is not intended that these illustrated embodiments or the terminology employed in describing them is to be limiting, but

I claim: 1. A dip tube combination adapted to be used with a hot water tank comprising:

an elongated tubular member;

one end of said member being flared radially outwardly;

an aperture formed in the wall of said member adjacent said one end; a sleeve molded to said one end of said member with a portion of said sleeve extending into said aperture; said sleeve further including portions on either side of the flared end of said tubular member;

thread means on the exterior surface of said sleeve;

hexagonal tool pads formed on the interior of said sleeve means; and

a flexible circumferential flange on said sleeve extending in a longitudinal directon away from said tubular member.

2. In combination with a water heater having an aperture formed in one wall thereof and a spud secured to the wall over the aperture;

a nipple threadedly secured at one end in said spud;

a dip tube extending through said nipple, spud and aperture into the interior of the water heater;

an externally threaded sleeve molded to the exterior end of said tube;

said molded sleeve being supported on the other end of said nipple;

a connecting sleeve threadedly engaged with said molded sleeve and said other end of said nipple; and

a conduit threaded into said connecting sleeve to a position adjacent said molded sleeve.

3. A joint for the introduction of water into a hot water heater comprising:

one wall of the heater having an aperture formed therean internally threaded spud secured to the wall over said aperture;

a dip tube extending through said spud and aperture into the interior of the heater;

an externally threaded sleeve molded to the exterior end of said tube;

said sleeve including a circumferential, longitudinally extending flange on the free end thereof;

said sleeve being in threaded engagement with said spud thereby supporting said tube;

tool pad means formed on the interior of said sleeve for receiving an appropriate tool for securing said sleeve and said member in the aperture of the wall of the heater;

a conduit threaded into said spud adjacent said sleeve whereby water in said conduit is conducted through said tube into the water heater; and

said flange is dimensioned such that said conduit compresses said flange as the conduit is threaded into the spud whereby the flange is deformed radially into sealing engagement with the threaded wall of the spud.

4. A joint for a dip tube combination adapted to extend through an opening in the wall of a. hot water heater said joint comprising:

an elongated tubular member;

one wall of the heater having an aperture formed therein with an internally threaded spud secured to the wall over said aperture;

one end of said member being flared radially outwardly;

an aperture formed in the wall of said member adjacent said one end;

an externally threaded sleeve being in threaded engagement with said spud and being molded to said one end of said member with a portion of said sleeve extending into said aperture of said member;

said sleeve further including portions disposed on either side of said flared end of said member and a circumferential, longitudinally extending flange extending away from said member; and

tool pad means formed on the interior of said sleeve.

References Cited UNITED STATES PATENTS 304,997 11/1905 Barr 28539 1,389,997 9/1921 Sedgwick 285--39 X 1,987,366 1/1935 Ford 28539 2,186,925 1/1940 Hooper et al 285158 X 2,378,901 6/1945 Amrheim et a1. 242-11832 2,793,059 5/1957 Woodling 2853 82.4 X 2,814,862 12/1957 Hickethorn 28539 3,038,744 6/1962 Boylan 285239 X 3,105,707 10/ 1963 Jacobson 28539 3,167,330 1/ 1965 Draudt 2857 FOREIGN PATENTS 485,409 10/1917 France.

CARL W. TOMLIN, Primary Examiner.

D. W. AROLA, Assistant Examiner. 

